1. Technical Field
The present invention relates to an apparatus for protecting an occupant of a vehicle during a collision, and is particularly directed to an apparatus for preventing false ignition of an ignitable pyrotechnic transmission line which, when ignited, actuates a safety device.
2. Background Art
The use of an ignitable pyrotechnic transmission line to actuate a vehicle safety device is known. Typically, a pyrotechnic transmission line has one end connected to the safety device and the other end connected to a firing manifold. An ignitable blasting cap known as a microdet is disposed in the firing manifold. The microdet ignites when subjected to a firing signal of sufficient magnitude and duration. The firing signal of sufficient magnitude and duration is provided by a sensor which senses a vehicle collision. When ignited, the microdet generates gas and flame. The gas and flame ignite the pyrotechnic transmission line which in turn actuates the safety device.
A problem can arise if no actual vehicle collision has occurred, but the microdet nonetheless ignites. The resulting ignition of the pyrotechnic transmission line would cause undesired actuation of the safety device. Thus, it is desirable to ignite the pyrotechnic transmission line only in the event of an actual vehicle collision.